Workpiece gripper having vibrating means thereon

ABSTRACT

A pusher furnace for heating workpieces having an ejecting apparatus which grips each workpiece emerging from the furnace exit, vibrates the workpiece to prevent fusing of the workpiece with the one immediately behind it and withdraws the workpiece at the appropriate time.

United States Patent [191 Seulen et a1.

[4 1 Nov. 12, 1974 1 WORKPIECE GRIPPER HAVING VIBRATING MEANS THEREON [75] Inventors: Gerhard Seulen; Friedrich Scheffler,

both of Remscheid, Germany [73] Assignee; AEG-Elotherm GmbH,

Remscheid-Hasten, Germany [22] Filed: Jan. 16, 1973 1211 Appl. No.: 324,145

[31)] Foreign Application Priority Data Mar. 18, 1972 Germany 2213249 [52] US. Cl. 214/27, 432/239 [51] Int. Cl. F27b 9/38 [58] Field of Search 214/23, 27, 28; 432/134,

[56] References Cited UNITED STATES PATENTS 2,368,615 2/1945 Reese 214/27 3,575,301 4/1971 Panissidi .1 214/1 BC FOREIGN PATENTS OR APPLICATIONS 1,221,657 7/1966 Germany .1 214/27 Primary ExaminerRobert G. Sheridan Attorney, Agent, or Firm-Cushman, Darby & Cushman [57] ABSTRACT A pusher furnace for heating workpieces having an ejecting apparatus which grips each workpiece emerging from the furnace exit, vibrates the workpiece to prevent fusing of the workpiece with the one immediately behind it and withdraws the workpiece at the appropriate time.

10 Claims, 4 Drawing Figures PATENTEDNUV l 2 I574 SHEET 1 BF 2 PATENTEDHUY 12 1974 SHEET 2 OF 2 WORKPIECE GRIPPER HAVING VIBRATING MEANS THEREON 1 delivered to a forging machine. to their hot forming temperature in a pusher furnace which may be gas, oil or-inductively heated. In the case of steel thistemperature isusually between l200 and 1280 C. For the purpose of conveyingthe small ingotsthrough thefurnace a lifting. beam-systemmay be useful, although the mechanicalcomplexitiesof such a system involve a con-. siderable. expenditure. .Mechanically much simpler than a liftingbeam type. of furnace isa pusher furnace in whicha column of consecutive ingots is conveyed. intermittently through the fumace to the exitend by a pusher: which. at. eachforward step advances the column by the lengthof one ingot. However, the advantage afforded by the greater simplicity of thisarrange: ment is; offset by the drawbackthat the forces acting between the ingots during the feed steps. tend to cause the contacting facesof consecutive ingots in the high temperaturezone of the furnace to fuse andweld together. Attempts to separate ingots that have thus fused together by providing a breaker device at the furnace exit have not given-satisfactory results since, particularly-at. final temperatures exceeding 1,250 C, the fused "steel. ingots are extremely firmly stucktogether when theyleave the. furnace exit. To. enable ingots to bereliably separatedvery powerful bendingor percussion devices would. be needed and, preferably these would have to work: automatically. Such equipment cannot in practicebeproduced at a-reasonable cost.

' It is the object of the presentinventionto provide a. pusher furnace, particularly an inductively heated pusherfurnace which: ejects the workpieces, particularly small steel ingots that have been-heated inside'the furnace, consecutively at predetermined intervals, and

which prevents the workpiecesfrom stickingor weld.- ing together, the fully heated. workpiecebeing pulled fromithe. furnace exit. Accordingto the invention this is achieved .by theprovision of ejector means at the furnace exit comprising. ejecting. elements which are mountedin aholder and adapted to grip the flanks of the workpiece and to. move. it forwards, the holder being supportedso that. it can move. in aidirectionnormal to. the direction'of advanceof. the work, and avibratorrbeing coupledthereto.

D'uring; operation the described ejector elements apply vibratorymotion to. the. fullypreheated work'- piecewaitinggatthefurnaceexit and they thereby prevent itstrailinggend in the.hightemperaturezoneof the. furnace from beingweldeclto the. abutting leading-end of the next following. workpiece.

In order to permit theejector elements to perform such vibratory movements their holder is preferably mounted. with the. interposition of elastieelements.

In an alternative preferred embodiment of the invention, the .holderis supportedina manner permittingrotationof theelements about an axisparallel to. the direction of workpiece. advance. Atrotary vibratory motioncan'thus beimparted to the holder and its ejector: elements.

According to another feature of the invention, the ejector elements may be constituted by clamping members and the holder may incorporate means for opening and closing. the clamping members. In such an arrangement the holder together with the vibrator may. with advantage be mounted in a carriage or slide which is movable in. the direction of workpiece advance so that by moving the slide the workpiece gripped by. the clamping members can be withdrawn from the furnace exit.

In yet another preferred embodiment of the invention the ejector elements for withdrawing the workpieces in advancing direction are constituted by driven bodiesadapted-to roll on the workpiece surface, particularly in the form of rollers, cylinders or endlesstrav'el ling chains.

The invention will be hereinafter described in greater detail, reference being made to the drawings in which:

FIG. 1 shows the exitof an'inductively heatedpusher furnace for heating small steel ingots and shows associ-- ated ejector equipment adjacent the furnace exit.

FIG. 2. shows the ejector equipment in a section taken on the. line A B in FIG. 1.

FIG. 3 shows a modified holder for the clamping elements. I

FIG. 4 shows a further embodiment of the ejector.

Referring. to FIG. 1, the pusher furnace is equipped with a liquid-cooled induction coill andcontains slide rails 2 for supporting small steel ingots 3 that are to be heated. Adjacent the furnace exit is an ejector device comprising tong-like clamping members4 mounted ona holder 5 which contains means -(:notshown) for con trollably openingand closing clamping members 4; The holder S-is mounted on a slide 8'with the interposition of springelements 6. which permit-a vibratory motion normal to the direction-of advance through the pusher furnaceto be imparted to the holder by a vibratorTin; themanner indicated by arrows 9. i

The slide8itself together with its clamping members 4,.its holder Sand the vibrator Tare slidably movable onbars 10in relationto the furnace inthe direction in which the workpiecesadvance.

Let it be assumed that'after the completion of the ejection of one ingot the next fully heated ingot at the head of acolumn of ingots occupies a position in the furnace exit as illustrated in FIG. I.

The leading. end of this fully heated block 3-then projects slightly from the furnace exit, whereasiits tailh end 11 is abutted by the second block stillin thehigh equipment is now advanced towards the fumaceexit into theposition in'FIG. 1; the clamping m'embers are closedand grip the ingot 3 that isto be-ejected. The;- vibrator isstarted and impartsto the ingot 3' a-wvib'ra-, tory motion in a direction normal to thedirection-in'. which?-: the block. advances. The relative motionthus producedjbetween the ingot that is to be ejected and] thernextlingot in the columnprevents thesetwo ingots from sticking or fusing; together and any incipient" fu-. sion or weld-at their point of contact will be nullified:

Simultaneously with the next'advancingstep of the;

in the direction of the arrow 12 and then deposited on I a transferring means 19 when the clamping members 4 open. The transferring means carries the ingot to the forging machine. The withdrawal of the small ingot 3 may with advantage already begin before the next ingot is advanced by the next step of the pusher.

FIG. 3 is a modified holder for the clamping members. This is attached without the interposition of spring elements to the slide or carriage of the ejector equipment, the slide or carriage being movable in the direction in which the workpieces travel through the furnace. The holder 5' which serves for supporting the clamping members 4' and their actuating means in this embodiment has a cylindrical external surface and is rotatably mounted in a frame-like slide 8 fitted with rollers 13. The frame structure itself is bodily slidably movable along bars 10' extending in the direction of advance of the ingots. By means of a vibrator 7 a rotary oscillation can be applied to the holder 5', the clamping members 4 and to the ingot which they have gripped. This oscillation has an analogous effect to that achieved in the previously described embodiment shown in FIGS. 1 and 2. The present modification has the additional advantage that the small ingot 3' which has been separated from the following column of ingots and withdrawn from the furnace exit can be deposited for instance in a chute 20 and thus removed after it has been released by the clamping members 4".

This latter advantage is also achieved in a further embodiment of the ejector shown in FIG. 4. This can be used with particular advantage when the length of the ingots is considerable in relation to their diameter. Contrary to the previously described embodiments of the ejector equipment in the arrangement of FIG. 4, the ejector elements include conical rollers 14 which are rotatably mounted on a shaft 15 that can be driven and that extends across the direction of advance of the ingots. The holder 5" is associated with a vibrator 7" and supported from a pedestal 17 in the furnace frame with the interposition of spring elements 6'.

In this embodiment the column of ingots is advanced in the furnace at each feeding step so that the leading ingot which is fully heated and ready to be ejected can be engaged by the ejector rollers 14. Vibratory motion in the direction of the arrows 18 is imparted to this ingot by the vibrator 7" acting through the holder 5", the shaft 15 and the conical ejector rollers 14. This vibration prevents the ingots that are about to be ejected from sticking or welding to the next following ingot inside the furnace or at least it causes any incipient fusion 'or weld to be rebroken. Owing to the high frictional resistance between the hot ingots 3' and the ejector rollers l4, rotation of the rollers which now begins causes the ingot that is to be ejected to be pulled out of the furnace exit, to be deposited for instance on a chute 20 leading to an associated forging machine. If the available; friction of the pair of rollersshould not be sufficient, then several synchronously driven roller pairs may be provided in tandem in the direction of advance of the work.

According to a further modification of FIG. 4, not exemplified in the drawings, a second pair of rollers may be mounted above the described roller pair on a vertically movable horizontal shaft. Each feeding step advances the next ingot that is to be ejected between the two roller pairs. The upper roller pair is then lowered on the ingot and both pairs grip the ingot that is to be ejected like clamping members.

Many changes and modifications in the above described embodiments of the invention can be made without departing from the scope of the invention. Accordingly, that scope is intended to be limited only by the scope of the appended claims.

What is claimed is:

1. In a pusher furnace for inductively heating workpieces to their hot forming temperature before they are ejected at predetermined intervals at the furnace exit, the improvement comprising means for ejecting the fully heated workpieces at the furnace exit including ejecting elements mounted on a holder and adapted to grip the flanks of the workpiece and to withdraw the same in the direction of workpiece advance, said holder being supported so that it can move in a direction normal to the direction of workpiece advance, and a vibrator being coupled to said holder said vibrator preventing fusing of the gripped workpiece with one immediately therebehind.

2. In a pusher furnace according to claim 1, the further improvement comprising elastic means mounting said holder.

3. In a pusher furnace according to claim 1, the further improvement comprising means for mounting said holder rotatably about an axis parallel to the direction of workpiece advance. 4. In a pusher furnace according to claim l, the improvement wherein the ejecting elements include clamping members and the holder includes means for opening and closing the clamping members.

5. In a pusher furnace according to claim 4, the improvement wherein said holder together with the vibrator is mounted in a carriage which is movable inthe direction of workpiece advance. p

6. In a pusher furnace according to claim 1, the im provement comprising means for propelling the workpieces in the direction of workpiece advance including driven bodies for rolling on the workpiece surface.

7. In a pusher furnace according to claim 6, the improvement wherein said ejecting elements include driven rollers.

8. Apparatus for ejecting hot workpieces from a pusher furnace comprising:

means for gripping a workpiece at the exit of said furnace,

means for moving said gripping means to withdraw the gripped workpiece from said furnace, and

means coupled to said gripping means for vibrating said gripping means and the gripped workpiece said means for vibrating preventing fusing of the gripped workpiece with one immediately therebehind.

9. Apparatus as in claim 8 wherein said gripping means includes tong-like, clamping members, a movablecarriage, means mounting said clamping members, elastic means connecting said carriage to said clamping members mounting means, and means connecting said vibrating means to said clamping members mounting means.

10. Apparatus as in claim 8 wherein said gripping means includes clamping members, means for mounting said clamping members for rotatory vibratory motion, and means for connecting said clamping members mounting means to said vibrating means.

in k m n 

1. In a pusher furnace for inductively heating workpieces to their hot forming temperature before they are ejected at predetermined intervals at the furnace exit, the improvement comprising means for ejecting the fully heated workpieces at the furnace exit including ejecting elements mounted on a holder and adapted to grip the flanks of the workpiece and to withdraw the same in the direction of workpiece advance, said holder being supported so that it can move in a direction normal to the direction of workpiece advance, and a vibrator being coupled to saId holder said vibrator preventing fusing of the gripped workpiece with one immediately therebehind.
 2. In a pusher furnace according to claim 1, the further improvement comprising elastic means mounting said holder.
 3. In a pusher furnace according to claim 1, the further improvement comprising means for mounting said holder rotatably about an axis parallel to the direction of workpiece advance.
 4. In a pusher furnace according to claim 1, the improvement wherein the ejecting elements include clamping members and the holder includes means for opening and closing the clamping members.
 5. In a pusher furnace according to claim 4, the improvement wherein said holder together with the vibrator is mounted in a carriage which is movable in the direction of workpiece advance.
 6. In a pusher furnace according to claim 1, the improvement comprising means for propelling the workpieces in the direction of workpiece advance including driven bodies for rolling on the workpiece surface.
 7. In a pusher furnace according to claim 6, the improvement wherein said ejecting elements include driven rollers.
 8. Apparatus for ejecting hot workpieces from a pusher furnace comprising: means for gripping a workpiece at the exit of said furnace, means for moving said gripping means to withdraw the gripped workpiece from said furnace, and means coupled to said gripping means for vibrating said gripping means and the gripped workpiece said means for vibrating preventing fusing of the gripped workpiece with one immediately therebehind.
 9. Apparatus as in claim 8 wherein said gripping means includes tong-like, clamping members, a movable carriage, means mounting said clamping members, elastic means connecting said carriage to said clamping members mounting means, and means connecting said vibrating means to said clamping members mounting means.
 10. Apparatus as in claim 8 wherein said gripping means includes clamping members, means for mounting said clamping members for rotatory vibratory motion, and means for connecting said clamping members mounting means to said vibrating means. 